An Uncertain Winter Forecast from the National Weather Service
The upcoming winter will be influenced by neither an El Nino nor a La Nina atmospheric pattern, so pinning down a long term forecast is difficult.
Chief Meteorologist Bob Nester said there are predictable patterns with either an El Nino or a La Nina winter.
“I’ll give you an example,” he said. “In a strong El Nino system when the water is warmer than normal, we almost always have lower than normal snow pack and warmer than normal temperatures especially over the mountains” said Nester. “Conversely, during La Nina’s, it’s snowier than normal.”
Nester said even though this winter is being termed ‘neutral’ as far as patterns are concerned, he said there can still be weather extremes.
“There is one thing that I found interesting,” he said. “During neutral years, and there have been about 20 of them over the last 60 years, some of those 10 coldest events happened during those neutral years, and the frequency of arctic events is a little bit higher than normal, but that doesn’t mean it happens every year.”
Nester said there can be major snow events, as well.
“Some of our weather extremes have occurred in neutral years, so it doesn’t mean we’re not going to have winter,” he said. “Our snowiest event, if you were here in 1996 and 97 during Christmas of that year, we had over 40 inches of snow in a week, and that was during an El Nino neutral year. It just so happened that the pattern lined up perfectly for that type of event.”
Nester said instead of counting on any long range forecast, he advises Missoula residents to pay close attention to forecasts looking forward a few weeks forward for planning purposes, as they can be much more accurate.
Nester said we will still have a ‘Montana winter’, with periods of snow and cold temperatures from now through March.